A method for analyzing toothed whale motion sonar detection signals

Abstract

The invention provides a toothed whale motion sonar detection signal analysis method, comprising the following steps: step 1: building a toothed whale motion sonar detection experimental system; step 2: carrying out a toothed whale motion sonar detection experiment; step 3: receiving a video signal collected by a video acquisition module, and intercepting a time period when the toothed whale has a swimming detection target behavior; step 4: receiving array element data collected by a sound acquisition module, intercepting array element signals in the time period when the toothed whale swims to detect the target, and obtaining a sound signal x(t) of the toothed whale motion detection target through array processing; step 5: analyzing the video signal of the toothed whale swimming to detect the target, analyzing the behavior trajectory of the toothed whale when swimming to detect the target, and summarizing the behavior law of the toothed whale swimming to detect the target; step 6: analyzing the sound signal x(t) of the toothed whale swimming to detect the target; step 7: jointly analyzing the sound signal and behavior trajectory of the toothed whale when swimming to detect the target, and summarizing the sound-motion linkage law of the toothed whale motion detection target.

Description

Technical Field

[0001] The invention relates to the technical field of sonar detection and analysis of toothed whale movements, and in particular to a method for analyzing sonar detection signals of toothed whale movements. Background Art

[0002] After a long period of evolution, toothed whales such as dolphins and finless porpoises have the ability to detect, locate and identify underwater, which is beyond the capabilities of artificial sonar. When toothed whales detect targets in a free-moving state, they will constantly adjust their sound signals according to changes in the environment, target distance, target attributes, etc.

[0003] Studying the vocalization patterns and behavioral trajectories of toothed whales when detecting targets underwater plays an important role in better understanding the mechanism of biological sonar.

[0004] At present, there are few experiments on sonar detection of toothed whales, and there is a lack of analysis methods for sonar detection signals of toothed whales. When there are multiple toothed whales at the same time, they may make sounds at the same time. Relying on cameras alone can only determine the approximate position of toothed whales, and it is impossible to accurately extract the sound signals of toothed whales currently detecting targets, which greatly increases the difficulty of analyzing the target signal analysis of toothed whale movement detection. How to accurately extract the sound signals and behavior trajectories of toothed whales in a complete swimming detection process is crucial for analyzing the sonar detection signals of toothed whales. Summary of the invention

[0005] The problem to be solved by the present invention is to provide a method for analyzing toothed whale motion sonar detection signals in view of the above-mentioned deficiencies in the prior art, which solves the problem of high difficulty in analyzing toothed whale motion detection target signals in the prior art.

[0006] The above-mentioned invention object of the present invention is achieved through the following technical scheme: a method for analyzing toothed whale motion sonar detection signals, the analysis method comprising the following steps:

[0007] Step 1: Building a toothed whale motion sonar detection experimental system, the experimental system includes a sound acquisition module, a video acquisition module, a noise field generation module, and a target placement module;

[0008] Step 2: Conduct a toothed whale motion sonar detection experiment. First, use the target placement module to place the toothed whale detection target, then start or shut down the noise field generation module to allow the toothed whale to perform target detection.

[0009] Step 3: Receive the video signal collected by the video acquisition module, intercept the time period with a clear start and end time of the toothed whale's swimming detection target behavior, and record the start time t start and end time t end ;

[0010] Step 4: Receive the array data collected by the sound collection module, and intercept the array element signals x1(t), x2(t),…, x1(t) in the target detection period of the toothed whale. M (t), t∈(t start ,t end ), M is the number of array elements, and the array element signals within the detection time period are divided into P segments at equal intervals, and the duration of each segment is

[0011] Step 5: Analyze the video signal of the toothed whale swimming to detect the target, analyze the behavior trajectory of the toothed whale when swimming to detect the target, and summarize the behavior rules of the toothed whale swimming to detect the target;

[0012] Step 6: Analyze the sound signal x(t) of the toothed whale swimming detection target;

[0013] Step 7: Combined analysis of the vocalization signals and behavioral trajectories of toothed whales when they swim and detect targets, and summary of the vocalization-movement linkage rules of toothed whales when they move and detect targets.

[0014] The present invention is further configured as follows: Step 1 comprises the following steps:

[0015] 1.1 Build the sound collection module: The sound collection module includes a multi-channel hydrophone array, a movable hydrophone bracket, and a multi-channel synchronous data collector;

[0016] 1.2 Build a video acquisition module: The video acquisition module includes an underwater high-speed camera and a surface camera. Multiple surface cameras and underwater high-speed cameras are installed according to the actual situation of the experimental site to ensure that there is no visual blind spot;

[0017] 1.3 Build a noise field generation module: The noise field generation module includes a signal source, a power amplifier, and a transmitting transducer;

[0018] 1.4 Build the target placement module: The target placement module includes a stationary target placement sub-module and a moving target placement sub-module. The stationary target is suspended in the experimental pool by a counterweight device, and the moving target is directly placed in the experimental pool.

[0019] The present invention is further configured as follows: the step 1.1 also includes: according to the actual situation of the experimental water pool, selecting the placement position of the multi-channel hydrophone array, using a movable hydrophone bracket to install the multi-channel hydrophone array, the multi-channel hydrophone array is arranged according to the half wavelength of the center frequency of the toothed whale sound, and the multi-channel hydrophone array is arranged into a linear array, a vertical array, an L-shaped array, and a cross array through the movable hydrophone bracket, and the output end of each hydrophone in the multi-channel hydrophone array is connected to the input end of the multi-channel synchronous data collector.

[0020] The present invention is further configured as follows: Step 2 comprises the following steps:

[0021] Step 2.1: First, use the target placement module to place the stationary target and the moving target, and then let the toothed whales conduct target detection experiments in a free-moving state. The target detection experiments include stationary target detection experiments and moving target detection experiments;

[0022] Step 2.2: Choose whether to start the noise field generation module, emit noises of different frequency bands, different intensities, and different noise sources to simulate environmental changes, and record the changes in the sound signals and behavioral trajectories of toothed whales when detecting targets under environmental changes.

[0023] The present invention is further configured as follows: the video signal collected by the receiving video acquisition module refers to the video signal received from the underwater high-speed camera, and the visual blind spot of the video screen of a single underwater high-speed camera is filled by comparing the recorded screens of multiple underwater high-speed cameras.

[0024] The present invention is further configured as follows: Step 4 further includes: performing the following processing on each segment of data:

[0025] 4.1: Divide the entire space into N equally spaced positions, θ j =180° / N, j=1,2,…,N, perform omnidirectional beamforming on the multi-channel array data to obtain omnidirectional time domain beam signals t is the time;

[0026] 4.2 The time domain beam signals in N directions are screened one by one, and the direction (θ 01 ,θ 02 );

[0027] 4.3 Pair (θ 01 ,θ 02 ) to filter the time domain beam signals within the azimuth and extract the time domain beam azimuth with the largest amplitude. The time domain beam signal of this azimuth is time period t i Toothed whale vocalizations

[0028] 4.4 After performing the above operations on all P segment data, the complete toothed whale swimming detection target time period (t start ,t end )

[0029] The present invention is further configured as follows: Step 6 comprises the following steps:

[0030] 6.1: Taking the pulse train in the sound signal x(t) as the analysis unit, analyze the number of pulses, pulse interval, pulse envelope, and pulse train length of different pulse trains;

[0031] 6.2: Taking a single pulse in the sound signal x(t) as the analysis unit, analyze the pulse width, frequency band, spectrum, peak frequency, center frequency, and beam width of a single pulse;

[0032] 6.3: Compare the pulse train and single pulse parameters emitted by toothed whales in the process of swimming and detecting targets, and count the mean, variance, first-order moment and higher-order moment of the pulse train and single pulse parameters, and summarize the vocalization rules of toothed whales in the process of detecting targets in free movement;

[0033] 6.4: Compare the pulse train and single pulse parameters of toothed whales when detecting different targets, count the mean, variance, first-order moment, and higher-order moment of the pulse train and single pulse parameters, and summarize the vocalization patterns of toothed whales when detecting different targets.

[0034] In summary, the beneficial technical effects of the present invention are:

[0035] (1) The toothed whale motion sonar detection experimental system provided by the present invention can freely select the placement position of the hydrophone array according to the shape of the experimental pool through the movable hydrophone bracket, and is easy to install, simple and flexible; the noise field generation module can simulate environmental changes and study the changes in the sound signals of toothed whales under different environmental conditions; the target placement module includes two parts, namely, the stationary target placement and the moving target placement, which can fully study the sound signal patterns and behavior trajectory patterns of toothed whales detecting stationary targets and moving targets.

[0036] (2) Based on the array processing, the omnidirectional time-domain beam signal amplitude comparison and video signal joint confirmation method can accurately extract the toothed whale sound signal of the current detection target, solving the problem of difficult signal distinction when multiple toothed whales make sounds at the same time.

[0037] (3) Conduct multi-dimensional analysis of toothed whale motion detection target signals, including vocalization signal analysis, behavioral trajectory analysis, and analysis of the linkage between vocalization and movement. The vocalization signal includes pulse train feature analysis and single pulse signal feature analysis. The toothed whale motion detection target patterns are comprehensively analyzed from multiple angles and dimensions. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a flow chart of the toothed whale motion sonar detection signal analysis method of the present invention;

[0039] Figure 2 It is a block diagram of the toothed whale movement sonar detection experimental system of the present invention;

[0040] Figure 3 is a flow chart of steps 4, 5, 6, and 7 of the present invention;

[0041] Figure 4It is an omnidirectional time domain beam signal diagram at a certain moment in the present invention;

[0042] Figure 5 It is a time domain waveform diagram of two pulse trains when the finless porpoise swims and detects a target in the present invention;

[0043] Figure 6 It is a time domain waveform diagram and a spectrum diagram of two pulses when the finless porpoise swims and detects a target in the present invention. DETAILED DESCRIPTION

[0044] In order to make the technical means, creative features, objectives and functions achieved by the present invention clearer and easier to understand, the present invention is further explained below in conjunction with the accompanying drawings and specific implementation methods.

[0045] like Figure 1 As shown, the present invention proposes a method for analyzing toothed whale motion sonar detection signals, the analysis method comprising the following steps:

[0046] like Figure 2 As shown, step 1: build a toothed whale motion sonar detection experimental system, which includes a sound acquisition module, a video acquisition module, a noise field production module, and a target placement module.

[0047] 1.1 Build the sound collection module: The sound collection module includes a multi-channel hydrophone array, a movable hydrophone bracket, and a multi-channel synchronous data collector. According to the actual situation of the experimental pool, the placement of the multi-channel hydrophone array is selected, and the multi-channel hydrophone array is installed using the movable hydrophone bracket. The multi-channel hydrophone array is arranged according to the half-wavelength of the center frequency of the toothed whale's sound. The multi-channel hydrophone array is arranged into a linear array, a vertical array, an L-shaped array, and a cross array through the movable hydrophone bracket. The output of each hydrophone in the multi-channel hydrophone array is connected to the input of the multi-channel synchronous data collector.

[0048] 1.2 Build a video acquisition module: The video acquisition module includes an underwater high-speed camera and a surface camera. Multiple surface cameras and underwater high-speed cameras are installed according to the actual situation of the experimental site to ensure that there is no visual blind spot;

[0049] 1.3 Build a noise field generation module: The noise field generation module includes a signal source, a power amplifier, and a transmitting transducer;

[0050] 1.4 Build the target placement module: The target placement module includes a stationary target placement sub-module and a moving target placement sub-module. The stationary target is suspended in the experimental pool by a counterweight device, and the moving target is directly placed in the experimental pool.

[0051] In the step 1, the sound collection module includes a multi-channel hydrophone array, a multi-channel synchronous data collector, and a movable hydrophone bracket. The multi-channel hydrophone array is installed in the experimental water pool through the movable hydrophone bracket. The multi-channel hydrophone array is arranged in different formations such as a linear array, a vertical array, an L-shaped array, and a cross array through the movable hydrophone bracket. The multi-channel hydrophone array adaptively adjusts the array according to the shape of the experimental water pool to meet the needs of signal resolution at different directions or depths. The sound collection module has strong adaptability and is not limited to a specific experimental water pool.

[0052] Step 2: Conduct a toothed whale motion sonar detection experiment. First, use the target placement module to place the toothed whale's detection target, and then start or shut down the noise field generation module to allow the toothed whale to perform target detection.

[0053] Step 2.1: First, use the target placement module to place the stationary target and the moving target, and then let the toothed whales conduct target detection experiments in a free-moving state. The target detection experiments include stationary target detection experiments and moving target detection experiments;

[0054] Step 2.2: Choose whether to start the noise field generation module, emit noises of different frequency bands, different intensities, and different noise sources to simulate environmental changes, and record the changes in the sound signals and behavioral trajectories of toothed whales when detecting targets under environmental changes.

[0055] In step 2, the detection targets are divided into stationary targets and moving targets. In this embodiment, the stationary targets are buoys, floating boxes, etc., which are suspended in the experimental water pool by setting a counterweight device at the bottom. The counterweight device includes heavy objects such as stones that sink to the bottom and a connecting rope connected to the stationary target. The moving targets are buoys, floating boxes, etc., which are directly placed in the experimental water pool. The types of detection targets can also be selected as objects of different materials, sizes, and shapes as needed. By using the above-mentioned experimental method, the detection rules of toothed whales for different detection targets in a free motion state can be obtained, and the changes in sound signals and behavior trajectories of toothed whales during target detection can also be observed when the environmental noise changes.

[0056] Step 3: Receive the video signal collected by the video acquisition module. The video signal collected by the video acquisition module refers to receiving the video signal of the underwater high-speed camera. Compare the recorded images of multiple underwater high-speed cameras to fill the visual blind spot of the video image of a single underwater high-speed camera, intercept the time period with a clear start and end time of the toothed whale's swimming detection target behavior, and record the start time t start and end time t end .

[0057] In step 3, the visual blind spots of a single underwater high-speed camera video image are supplemented by comparing the recorded images of multiple underwater high-speed cameras, so that there are no visual blind spots.

[0058] like Figure 3 As shown, step 4: receiving the array data collected by the sound collection module, intercepting the array element signals x1(t), x2(t),…, x1(t) in the target detection time period of the toothed whale swimming. M (t), t∈(t start ,t end ), M is the number of array elements, and the array element signals within the detection time period are divided into P segments at equal intervals, and the duration of each segment is

[0059] Each piece of data is processed as follows:

[0060] 4.1: Divide the entire space into N equally spaced positions, θ j =180° / N, j=1,2,…,N, perform omnidirectional beamforming on the multi-channel array data to obtain omnidirectional time domain beam signals t is the time;

[0061] 4.2 The time domain beam signals in N directions are screened one by one, and the direction (θ 01 ,θ 02 );

[0062] 4.3 Pair (θ 01 ,θ 02 ) to filter the time domain beam signals within the azimuth and extract the time domain beam azimuth with the largest amplitude. The time domain beam signal of this azimuth is time period t i Toothed whale vocalizations

[0063] 4.4 After performing the above operations on all P segment data, the complete toothed whale swimming detection target time period (t start ,t end )

[0064] In step 4, in this embodiment, the number of array elements is M=32, and the omnidirectional beams are divided into N=48 beams. The multi-channel hydrophone array is arranged at the edge of the experimental pool, and the multi-channel hydrophone array is a linear array. During the experiment, the area in front of the multi-channel hydrophone array is divided into N directions. During the experiment, there are 5 finless porpoises in the experimental pool at the same time. Figure 4Given the omnidirectional time domain signal at a certain moment, we can see that some adjacent beams have similar waveforms, but different amplitudes. This is because the sound signal of a certain finless porpoise spreads to several beams at the same time, and the time domain beam with the largest amplitude is the sound signal of the finless porpoise. There are also time domain beams in different directions with significantly different waveforms, indicating that more than one finless porpoise is making sounds at this time. First, we find the approximate direction of the toothed whale that is currently detecting the target based on the video signal at that moment, and then select the time domain beam with the largest amplitude direction from the several beams at that direction as the sound signal of the toothed whale detecting the target at the current moment.

[0065] like Figure 3 As shown, step 5: analyze the video signal of the toothed whale swimming to detect the target, analyze the behavior trajectory of the toothed whale when swimming to detect the target, and summarize the behavior rules of the toothed whale swimming to detect the target.

[0066] In step 5, analyzing the behavior trajectory of toothed whales in detecting targets in a free-motion state helps to understand and analyze the detection strategy of toothed whale motion sonar.

[0067] like Figure 3 As shown, step 6: analyzing the sound signal x(t) of the toothed whale swimming detection target.

[0068] 6.1: Taking the pulse train in the sound signal x(t) as the analysis unit, analyze the number of pulses, pulse interval, pulse envelope, and pulse train length of different pulse trains;

[0069] In step 6.1, Figure 5 The time domain waveforms of two different pulse trains emitted by toothed whales in the process of swimming and detecting targets are given. It can be seen that the parameters of the two pulse trains, such as the number of pulses, pulse interval, pulse envelope and pulse train length, are different.

[0070] 6.2: Taking a single pulse in the sound signal x(t) as the analysis unit, analyze the pulse width, frequency band, spectrum, peak frequency, center frequency, and beam width of a single pulse;

[0071] In 6.2, Figure 6 The two pulse signals emitted by toothed whales during the detection process and their corresponding spectra are given. Figure 6 (a) and (c) are the pulse time domain waveforms. Figure 6 (b) and (d) are their corresponding spectra. It can be seen that the parameters of the two pulses, such as pulse width, frequency band, spectrum, peak frequency, center frequency, and beam width, are different.

[0072] like Figure 5 and 6As described above, referring to steps 6.1 and 6.2, it can be concluded that in the process of detecting targets, toothed whales will continuously adjust the type of transmitted signals according to environmental changes, target distance, target attributes, etc., and the pulse train and single pulse forms are constantly changing.

[0073] 6.3: Compare the pulse train and single pulse parameters emitted by toothed whales in the process of swimming and detecting targets, and count the mean, variance, first-order moment and higher-order moment of the pulse train and single pulse parameters, and summarize the vocalization rules of toothed whales in the process of detecting targets in free movement;

[0074] 6.4: Compare the pulse train and single pulse parameters of toothed whales when detecting different targets, count the mean, variance, first-order moment, and higher-order moment of the pulse train and single pulse parameters, and summarize the vocalization patterns of toothed whales when detecting different targets.

[0075] In step 6, the sound signals emitted by toothed whales when detecting targets of different shapes, sizes, and materials are divided into single pulses and pulse trains, and the parameters are analyzed separately, which helps to understand and analyze the characteristics and sound patterns of the sound signals emitted by toothed whales when detecting targets with moving sonar.

[0076] like Figure 3 As shown, step 7: jointly analyze the sound signals and behavior trajectories of toothed whales when swimming to detect targets, and summarize the sound-movement linkage rules of toothed whales when detecting targets.

[0077] The toothed whale motion sonar detection experimental system provided by the present invention can freely select the placement position and formation of the hydrophone array according to the shape of the experimental water pool through the movable hydrophone bracket, and is easy to install, simple and flexible; the noise field generation module can simulate environmental changes and study the changes in the sound signals of toothed whales under different environmental conditions; the target placement module includes two parts, namely, stationary target placement and moving target placement, and can fully study the sound signal laws and behavior trajectory laws of toothed whales detecting stationary targets and moving targets.

[0078] The method of all-round time-domain beam signal amplitude comparison based on array processing and joint confirmation of video signals can accurately extract the toothed whale sound signal of the current detection target, solving the problem of difficult signal distinction when multiple toothed whales make sounds at the same time.

[0079] A multi-dimensional analysis of the toothed whale movement detection target signals is conducted, including vocal signal analysis, behavioral trajectory analysis, and analysis of the linkage between vocalization and movement. The vocal signal includes pulse train feature analysis and single pulse signal feature analysis. The toothed whale movement detection target patterns are comprehensively analyzed from multiple angles and dimensions.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for analyzing toothed whale motion sonar detection signals, characterized in that: The analytical method comprises the following steps: Step 1: Build a toothed whale motion sonar detection experimental system, which includes a sound acquisition module, a video acquisition module, a noise field production module, and a target placement module. The target placement module includes a stationary target placement submodule and a moving target placement submodule. The stationary target is suspended in the experimental pool by a counterweight device, and the moving target is directly placed in the experimental pool; Step 2: Conduct a toothed whale motion sonar detection experiment. First, use the target placement module to place the toothed whale detection target, then start or shut down the noise field generation module to allow the toothed whale to perform target detection. Step 2.1: First, use the target placement module to place the stationary target and the moving target, and then let the toothed whales conduct target detection experiments in a free-moving state. The target detection experiments include stationary target detection experiments and moving target detection experiments; Step 2.2: Choose whether to start the noise field generation module, emit noises of different frequency bands, different intensities, and different noise sources to simulate environmental changes, and record the sound signals and behavioral trajectory changes of toothed whales when detecting targets under environmental changes; Step 3: Receive the video signal collected by the video acquisition module, intercept the time period with a clear start and end time of the toothed whale's swimming detection target behavior, and record the start time t start and end time t end ; Step 4: Receive the array data collected by the sound collection module, and intercept the array element signals x1(t), x2(t),…, x1(t) in the target detection period of the toothed whale. M (t), t∈(t start ,t end ), M is the number of array elements, and the array element signals within the detection time period are divided into P segments at equal intervals, and the duration of each segment is Step 5: Analyze the video signal of the toothed whale swimming to detect the target, analyze the behavior trajectory of the toothed whale when swimming to detect the target, and summarize the behavior rules of the toothed whale when swimming to detect the target; Step 6: Analyze the sound signal x(t) of the toothed whale swimming detection target; Step 7: Combined analysis of the vocalization signals and behavioral trajectories of toothed whales when they swim and detect targets, and summary of the vocalization-movement linkage rules of toothed whales when they move and detect targets.

2. The method for analyzing toothed whale motion sonar detection signals according to claim 1, characterized in that: Step 1 The following steps are involved: 1.1 Build the sound collection module: The sound collection module includes a multi-channel hydrophone array, a movable hydrophone bracket, and a multi-channel synchronous data collector; 1.2 Build a video acquisition module: The video acquisition module includes an underwater high-speed camera and a surface camera. Multiple surface cameras and underwater high-speed cameras are installed according to the actual situation of the experimental site to ensure that there is no visual blind spot; 1.3 Build a noise field generation module: The noise field generation module includes a signal source, a power amplifier, and a transmitting transducer; 1.4 Build the target placement module: The target placement module includes a stationary target placement sub-module and a moving target placement sub-module. The stationary target is suspended in the experimental pool by a counterweight device, and the moving target is directly placed in the experimental pool.

3. The method for analyzing toothed whale motion sonar detection signals according to claim 2, characterized in that: The step 1.1 also includes: selecting the placement position of the multi-channel hydrophone array according to the actual situation of the experimental pool, using a movable hydrophone bracket to install the multi-channel hydrophone array, arranging the multi-channel hydrophone array according to the half wavelength of the center frequency of the toothed whale's sound, arranging the multi-channel hydrophone array into a linear array, a vertical array, an L-shaped array, and a cross array through the movable hydrophone bracket, and the output end of each hydrophone in the multi-channel hydrophone array is connected to the input end of the multi-channel synchronous data collector.

4. The method for analyzing toothed whale motion sonar detection signals according to claim 2, characterized in that: The video signal collected by the receiving video acquisition module refers to the video signal received from the underwater high-speed camera, and the visual blind spot of the video image of a single underwater high-speed camera is filled by comparing the recorded images of multiple underwater high-speed cameras.

5. The method for analyzing toothed whale motion sonar detection signals according to claim 1, characterized in that: The step 4 also includes: performing the following processing on each segment of data: 4.1: Divide the entire space into N equally spaced positions, θ j =180° / N, j=1,2,…,N, perform omnidirectional beamforming on the multi-channel array data to obtain omnidirectional time domain beam signals t is the time; 4.2 The time domain beam signals of N directions are screened one by one, and the direction (θ 01 ,θ 02 ); 4.3 Pair (θ 01 ,θ 02 ) to filter the time domain beam signals within the azimuth and extract the time domain beam azimuth with the largest amplitude. The time domain beam signal of this azimuth is time period t i Toothed whale vocalizations 4.4 After performing the above operations on all P segment data, the complete toothed whale swimming detection target time period (t start ,t end ) 6. The method for analyzing toothed whale motion sonar detection signals according to claim 5, characterized in that: Step 6 The following steps are involved: 6.1: Taking the pulse train in the sound signal x(t) as the analysis unit, analyze the number of pulses, pulse interval, pulse envelope, and pulse train length of different pulse trains; 6.2: Taking a single pulse in the sound signal x(t) as the analysis unit, analyze the pulse width, frequency band, spectrum, peak frequency, center frequency, and beam width of a single pulse; 6.3: Compare the pulse train and single pulse parameters emitted by toothed whales in the process of swimming and detecting targets, and count the mean, variance, first-order moment and higher-order moment of the pulse train and single pulse parameters, and summarize the vocalization rules of toothed whales in the process of detecting targets in free movement; 6.4: Compare the pulse train and single pulse parameters of toothed whales when detecting different targets, count the mean, variance, first-order moment, and higher-order moment of the pulse train and single pulse parameters, and summarize the vocalization patterns of toothed whales when detecting different targets.

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